Implants for treatment of pathological conditions of the spine and/or locomotor system are known in the prior art. They are intended, for example, to mechanically stabilize a fracture, thus promoting the healing process or, in the case of endoprosthetic implants, to be permanently bonded to the bone.
PCT Publication No. WO 98/19699 describes the systemic administration of medications or hormones serving to promote osteosynthesis and thus to accelerate the healing process of the fracture. Examples of suitable means include growth factors such as IGF-I. Such systemic applications, however, can lead to undesirable side effects.
PCT Publication No. WO 93/20859 describes the fabrication of a thin foil or film consisting of a polylactic-acid/polyglycol-acid copolymer containing growth factors. The intent is to wrap a foil of that type, for instance, around fracture-fixation devices prior to their implantation. This is supposed to release the growth factors in localized fashion in the area of the fracture. In practice, however, this method is unsuitable since, for instance, a nail wrapped with a foil of that type cannot be inserted in the medulla in a way that the foil, which only loosely envelops the nail, actually reaches the point of its intended healing action.
In light of the foregoing, a need exists for an implant that promotes the healing process in pathological changes of the spinal column and locomotor system, especially by furthering osteosynthesis, and thus accelerating the healing of fractures or the integration of an implant.